Finally ready to run electrical, but have a couple questions first.

[chuey_316]

I have a 100a main panel that feeds a 100a sub panel in my basement. I want to make a run from my basement to a 60a sub panel in my garage, where I don't really use much power at one time as it's only me out there, so the full 60a will likely never be used. Anything that I use has been running fine from an 100ft extension cord to a 15a gfci without ever tripping a breaker.

I do want to have both both 120 and 240 available for use as well.

The only things I run would be things like an air compressor, 120v welder, table saw, skill saw, floor fan, a few led lights, a small radio, a single post 120v lift at some point, and hopefully a 240v mini split someday. Obviously being just me, these things are not used all at the same time. Worst case would be having a mini split running and either welding, or raising a vehicle when the compressor kicks on.

Now on to the questions.

The wire will run about 30-35 feet from the panel in my basement before exiting the house, then 40 feet to the garage before entering.

Am I correct in thinking that I will need to use 2-2-2-4 SER from the basement panel to the exterior wall, and then again from the exterior wall of the garage to the 2nd sub panel?

What is the easiest and cheapest ways of accomplishing this? I don't like the idea of a large junction box on the outside of my garage, but the LB's do not have the area stamped on them anywhere, nor have I been able to find any that do.

I already have 1-1/2" conduit, and 2 sweeping 90's for the 40ft underground run. I am looking at using either 2-2-2-4 aluminum URD, or individual lengths of XXHW-2. The XXHW-2 would be cheaper, but which would be easier to run through the conduit?

Should also note that I have turned on both of our ac units plus the dryer, oven, 3 ceiling fans, and a tv, then clamped my panels to get the worst possible case draw that we could have. The sub panel in the basement was sitting at 48a, and the main panel feeding it was right around 60a. Just turning off the oven and dryer dropped the main down to 13a.

 

[PCustoms]

Can you run conduit panel to panel?

If so use xhhw-2

 

[chuey_316]

Possibly. The walls in the garage are unfinished right now so I should be able to run extra conduit in there to the panel using a couple extra 90's or lb's if I bring the wire in and then assemble the last of the conduit over it.

Running conduit in the basement will be pretty hard, and will require a number of places where I'll have to connect 2 sweeping 90's together to get the correct angles, or transition from rigid conduit to flexible, but worth it to not have to use a large junction box on the outside of the garage.

I would have to do the same in the basement as inside the garage, and assemble the conduit over the wires piece by piece.

As for the xhhw-2 and conduit, is it worth using 1-1/2" conduit and lb's, or is is fairly easy to pull through 1-1/4? If so, I'll exchange the conduit I have and not only save a bit of cash, but have a smaller lb to look at on my outside wall.

 

[chuey_316]

Accidental post

 

[chuey_316]

Having trouble finding connectors large enough to go from 1-1/2" rigid to flex conduit. Since 1-1/4 flex is almost 1/2 the cost of 1-1/2, would something like this work for the transition? https://www.homedepot.com/p/Charlot...-Joint-Trap-Adapter-ABS00103W0600HD/313834565

I mean, I'm sure I could make it work, but would it be acceptable is the real question.

 

[wyliesdiesels]

I have a 100a main panel that feeds a 100a sub panel in my basement. I want to make a run from my basement to a 60a sub panel in my garage, where I don't really use much power at one time as it's only me out there, so the full 60a will likely never be used. Anything that I use has been running fine from an 100ft extension cord to a 15a gfci without ever tripping a breaker.

I do want to have both both 120 and 240 available for use as well.

The only things I run would be things like an air compressor, 120v welder, table saw, skill saw, floor fan, a few led lights, a small radio, a single post 120v lift at some point, and hopefully a 240v mini split someday. Obviously being just me, these things are not used all at the same time. Worst case would be having a mini split running and either welding, or raising a vehicle when the compressor kicks on.

Now on to the questions.

The wire will run about 30-35 feet from the panel in my basement before exiting the house, then 40 feet to the garage before entering.

Am I correct in thinking that I will need to use 2-2-2-4 SER from the basement panel to the exterior wall, and then again from the exterior wall of the garage to the 2nd sub panel?

Instead of using SER and then transitioning to an underground rated cable why not just use MHF all the way? you would have to put conduit in for the indoor portions of the run but it would allow you to avoid splicing and large j boxes...

What is the easiest and cheapest ways of accomplishing this? I don't like the idea of a large junction box on the outside of my garage, but the LB's do not have the area stamped on them anywhere, nor have I been able to find any that do.

I already have 1-1/2" conduit, and 2 sweeping 90's for the 40ft underground run. I am looking at using either 2-2-2-4 aluminum URD, or individual lengths of XXHW-2. The XXHW-2 would be cheaper, but which would be easier to run through the conduit?

URD not rated for indoor use unless its dual or triple rated RHH/RHW

Should also note that I have turned on both of our ac units plus the dryer, oven, 3 ceiling fans, and a tv, then clamped my panels to get the worst possible case draw that we could have. The sub panel in the basement was sitting at 48a, and the main panel feeding it was right around 60a. Just turning off the oven and dryer dropped the main down to 13a.

that isnt how a load calc is done...

 

[chuey_316]

Instead of using SER and then transitioning to an underground rated cable why not just use MHF all the way? you would have to put conduit in for the indoor portions of the run but it would allow you to avoid splicing and large j boxes...

That was the original plan, but I was trying to not have to run conduit in the walls or through my basement if I could. Plus XHHW-2 is way less money from what I've found.

URD not rated for indoor use unless its dual or triple rated RHH/RHW

Thanks. I was not aware of that.

that isnt how a load calc is done...

How should it be done? Clamping tells me exactly how many amps is being pulled through feeder wires in my panels, and when I have used online calculators like over at Mike Holts I came up with pretty much the same number.

 

[chuey_316]

I'm at the point now where I'm about to just go with the junction boxes and transitioning from XHHW-2 to SER.

It will cost about the same as all XHHW-2 plus the extra conduit, and I won't have to deal with the major hassle of running the conduit in the basement.

Still curious about the load calculation, and if there is any wiring other than the 2-2-2-4 SER that I can transition to and still run through the basement without conduit.

 

[wyliesdiesels]

How should it be done? Clamping tells me exactly how many amps is being pulled through feeder wires in my panels, and when I have used online calculators like over at Mike Holts I came up with pretty much the same number.

Mike holt used to have a load calc spreadsheet on his website. its gone now but here is another one you could try

https://www.ladbs.org/docs/default-source/forms/inspection-forms/sfd-electrical-vehicle-charger-service-load-calculation-form-in-form-00.pdf?sfvrsn=1ca8e453_20

 

[wyliesdiesels]

and if there is any wiring other than the 2-2-2-4 SER that I can transition to and still run through the basement without conduit.

unfortunately there is no such cable that exists. SER is the only cable you can run that doesnt require conduit indoors (other than NM-b which is prohibitively expensive at that size if you can even find it; i dont think NM-b comes in #2 but im not wasting my time searching)....

when you add up all the costs and time to splice wire on both ends, it may as well be cheaper to just run conduit the entire run and use MHF.... me personally i would rather spend the time running conduit in a basement if i could avoid 2 junction cans and splices which are more points of potential failure....

 

[chuey_316]

when you add up all the costs and time to splice wire on both ends, it may as well be cheaper to just run conduit the entire run and use MHF.... me personally i would rather spend the time running conduit in a basement if i could avoid 2 junction cans and splices which are more points of potential failure....

Price wise looks to be about the same or just a bit cheaper with xhhw-2 and ser, but my main factor is that as I stated, running conduit through my basement would be FAR more work.

I would need to use multiple 90's along a 30-40 ft span after coming through the wall with an LB. There is no section where I could run more than 4-5 feet straight at most before having to connect two 90's together to continue. Either that or hang the conduit so low that it gets hit every time I go down there.

I'd personally love to use use MHF the whole way as myself as well but the sheer amount of extra time and energy to do so just isn't worth it in this case.

Now running the XHHW-2 through the garage wall and to the sub panel in conduit is definitely doable. That would at least eliminate one junction box, and like you said, one failure point as well.

Would this be acceptable wire to transition to? https://prowireandcable.com/2-3c-al-ser-cable-w-ground/#productDescription

And are this style of splices decent, or is there a better option? https://www.homedepot.com/p/ASI-14-...le-Side-Entry-2-Ports-Black-AICS2-2/307769185

 

[PCustoms]

Delete

 

[chuey_316]

Sorry. Nevermind on the link for the SER wire. I can get it locally for a little less and not wait on shipping. Still interested in any input as far as the tap connectors or any other possibly better options though.

 

[wyliesdiesels]

yes those splice connectors are good

 

[chuey_316]

Thanks. So before I order the wire I just want to double check that what I am getting is correct.

I'll be ordering enough XHHW-2 to make 3 runs of 2awg, and one run of 4awg from the outside wall of my home to the garage, running through 1-1/2" pvc conduit from here https://shopwirenco.com/products/cto_2xhhw-al?_pos=2&_sid=ecc5fa9e0&_ss=r

Then I'll be ordering enough 2-2-2-4 SER to run inside to my basement sub panel and possibly inside the wall in my garage should I not be able to fit the conduit in the framing with the panel. That wire will come from here https://www.lowes.com/pd/Southwire-...er-Service-Entrance-Cable-By-the-Foot/4294349

So long as all that looks ok, I have one other question. Will a 6" junction box be big enough or will I need bigger? I'm seeing conflicting info on my searches of people saying they used a 6" with 2-2-2-4, and other claiming that you need bigger sizes ranging from 8 to 12".

I did find other connectors that are the same style but shaped differently that are about 1.5" wide and with the connections on opposite side which would save some space in the box.

More importantly than just will a 6" junction box work, is will a 6" pass under 2017 NEC code.

 

[75gmck25]

IIRC, the minimum size of the junction box is determined both by the wire size and by the conduit used to connect to the box. In general, the box dimension has to be at least 8 times the size of the conduit.

This article is based on the 2017 code. https://www.mikeholt.com/newsletter...1988#:~:text=You must size pull boxes,Splices.

 

[wyliesdiesels]

you should use a 12"x12" j box.... youll thank me later

 

[chuey_316]

you should use a 12"x12" j box.... youll thank me later

That big for 4 wires running in through bottom, and out the top? I know it's a major pain trying to fit too much wire in a smaller box when it's being coiled, but I figured this wouldn't be that bad.

Well looking at some 12x12 boxes, and the largest knock outs I'm seeing are 1".

Just use a hole saw to fit a 1-1/2" male adapter?

 

[wyliesdiesels]

Youre using PVC conduit right? Ive never seen a pvc junction box with knockouts but i suppose they could exist

Code requires the box to be 8x the conduit size

 

[wyliesdiesels]

deleted

 

[chuey_316]

Ok, so I have a list of everything else I need as far as conduit and wire, down to the the bushings, locknuts and adapters.

Next question is regarding the connection going into the Junction box. I have found a few 12x12x4 boxes online, but there is a 10x10x4 nearby at a box store, and already has knockouts in it that go up to 1-1/4.

If I use a 1-1/2" to 1-1/4" reducer and go into the box with a 1-1/4" male adapter, would I then be able to get away with a 10x10 seeing how 1.25x8 is 10, or am I misunderstanding the 8x rule?

My plan is to have the xhhw-2 come from the LB outside, through conduit in the wall, to a 2nd LB, then reduce to 1-1/4, and enter the box, and have the 2-2-2-4 exit the opposite side.

This would keep from having a large junction box on my outer wall, and it would be in a place that it would never be seen inside, yet still easily accessible.

 

[PCustoms]

Ok, so I have a list of everything else I need as far as conduit and wire, down to the the bushings, locknuts and adapters.

Next question is regarding the connection going into the Junction box. I have found a few 12x12x4 boxes online, but there is a 10x10x4 nearby at a box store, and already has knockouts in it that go up to 1-1/4.

If I use a 1-1/2" to 1-1/4" reducer and go into the box with a 1-1/4" male adapter, would I then be able to get away with a 10x10 seeing how 1.25x8 is 10, or am I misunderstanding the 8x rule?

My plan is to have the xhhw-2 come from the LB outside, through conduit in the wall, to a 2nd LB, then reduce to 1-1/4, and enter the box, and have the 2-2-2-4 exit the opposite side.

This would keep from having a large junction box on my outer wall, and it would be in a place that it would never be seen inside, yet still easily accessible.

Why back to back LB, can't you just go into the panel?

Also, and I'm not 100% on this, you can't splice inside the LB.

 

[chuey_316]

Why back to back LB, can't you just go into the panel?

This is where I am coming through he wall in the house to make the transition in the junction box.

Also, and I'm not 100% on this, you can't splice inside the LB.

Correct. I won't be making any splices inside the LB.

On the garage side I will be running the xhhw-2 straight to the panel in conduit. On the house side, I want to go from an LB outside, then through the wall with conduit to another LB where I can reduce down to 1-1/4, and run a 1-1/4 male fitting into the junction box.

 

[PCustoms]

This is where I am coming through he wall in the house to make the transition in the junction box.

Come out of the house right into the junction box, skip the 2 LB entirely.

 

[chuey_316]

The only way I could come through the wall and straight into the box with the area I have to work with would be to come into the back of the box, which would only leave about 2-1/2 or 3" from the race to the front access panel.

If I understand correctly, with a 1-1/4 race and an angle i will run need about 8", and there's no way I can come into the side of the junction box without 1st coming through the wall and making a turn due to the area it needs to go.

The junction box will also be inside the house in my basement stairwell. I didn't want it on the outside of the house in the area that the wiring will be ran, and this way it will be totally out of sight.

Now if I am misunderstanding the 8x rule on spacing, and I can run straight through the back of the box and make that tight of a turn then that would make for less conduit, but the box is 4" deep, and the male connector will probably stick through close to 1-1/2" or so, and face the front panel.

 

[chuey_316]

Found this image over at MikeHolt and edited it a bit. This is basically what I am thinking.

 

[sparky 1971]

The only way I could come through the wall and straight into the box with the area I have to work with would be to come into the back of the box, which would only leave about 2-1/2 or 3" from the race to the front access panel.

If I understand correctly, with a 1-1/4 race and an angle i will run need about 8", and there's no way I can come into the side of the junction box without 1st coming through the wall and making a turn due to the area it needs to go.

The junction box will also be inside the house in my basement stairwell. I didn't want it on the outside of the house in the area that the wiring will be ran, and this way it will be totally out of sight.

Now if I am misunderstanding the 8x rule on spacing, and I can run straight through the back of the box and make that tight of a turn then that would make for less conduit, but the box is 4" deep, and the male connector will probably stick through close to 1-1/2" or so, and face the front panel.

That's not what the 8X rule is. Go straight in the back of the box in one corner, go out the bottom in the opposite corner. And, per post #21, forget the 10X10 box. Get the 12X12.

 

[chuey_316]

That's not what the 8X rule is. Go straight in the back of the box in one corner, go out the bottom in the opposite corner. And, per post #21, forget the 10X10 box. Get the 12X12.

Thank you.

So it's ok to go in through the back and have 2 and 4 awg wires make that tight of a bend? The only reason I was looking at the 10x10 is because it's available locally, is 1/2 the cost of the 12x12, and already has 1-1/4 knockouts.

I'm not concerned about working in a slightly smaller space, so long as the 10x10 will meet the code requirement for space that is. If not then I will go 12x12, just rather not if I don't have to.

 

[sparky 1971]

Thank you.

So it's ok to go in through the back and have 2 and 4 awg wires make that tight of a bend?

It's not a very tight bend.

The only reason I was looking at the 10x10 is because it's available locally, is 1/2 the cost of the 12x12, and already has 1-1/4 knockouts.

I'm not concerned about working in a slightly smaller space, so long as the 10x10 will meet the code requirement for space that is. If not then I will go 12x12, just rather not if I don't have to.

You can use a 10X10, but you're going to wish for a 12X12 when you're trying to get the splices pushed back and then get the lid on. The only way I'd use a 10X10 was if a 12X12 was out of stock.

 

[PCustoms]

The only reason I was looking at the 10x10 is because it's available locally, is 1/2 the cost of the 12x12, and already has 1-1/4 knockouts.

Where are you?

I've never seen a 10x10 in stores, 12x12 is usually in stock.

As far as holes, a holesaw, cheap step bit or even a spade bit is all you need.

 

[chuey_316]

It's not a very tight bend.

Not doubting you, just want to make sure we're thinking the same thing before I move forward with the install.

The conduit would come through the wall, and straight into the back of the box via a male adapter, which would leave approximately 2-1/2 inches of space or slightly less between the end of the adapter and the front cover, and the xhhw-2 is ok to make the bend there? Or am I able to use a bushing though the back of the box, and glue my conduit to that rather than using the male adapter?

Where are you?

I've never seen a 10x10 in stores, 12x12 is usually in stock.

I'm in southern MI. The 12x12 was in stock for $80. The 10x10 was in stock for $40. I did some more searching though and found a 12x12 at a different store for $50, so I can grab that one instead, but both boxes are 4" deep.

There were no 12x12x6 boxes in stock. I did however find a 12x12x6 on Amazon that could be here in a couple days.

Is it worth getting the 12x12x6, or is a 12x12x4 easy enough to work with?

 

[sparky 1971]

Not doubting you, just want to make sure we're thinking the same thing before I move forward with the install.

The conduit would come through the wall, and straight into the back of the box via a male adapter, which would leave approximately 2-1/2 inches of space or slightly less between the end of the adapter and the front cover, and the xhhw-2 is ok to make the bend there? Or am I able to use a bushing though the back of the box, and glue my conduit to that rather than using the male adapter?

It will be fine, male adapter, bushing, and all the trimmings included. Loadcenter panels are 4" deep and wires a whole lot bigger than #2 make that bend all the time.

 

[chuey_316]

It will be fine, male adapter, bushing, and all the trimmings included. Loadcenter panels are 4" deep and wires a whole lot bigger than #2 make that bend all the time.

Good to hear. Thanks. Now as for the sub panel side. Since i'll still be running the xhhw-2 on that end, when the conduit comes to the knockout, do I just use another male adapter, lock nut, and bushing the same as with the junction box?

 

[sparky 1971]

Good to hear. Thanks. Now as for the sub panel side. Since i'll still be running the xhhw-2 on that end, when the conduit comes to the knockout, do I just use another male adapter, lock nut, and bushing the same as with the junction box?

Yes.

 

[cdoublejj]

throw a direct burial Ethernet from one building to the other while your at it. no futzing with wireless repeaters and signal strength. maybe not in the same conduit though

 

[chuey_316]

throw a direct burial Ethernet from one building to the other while your at it. no futzing with wireless repeaters and signal strength. maybe not in the same conduit though

I thought about doing that, although the wireless setup I have works really well.

I use a Netgear Nighthawk Mesh setup, and using just one satellite I am getting probably 75% of the speed that I get from ethernet, and with a 2nd satellite in the garage I can get very close to, if not full speed.

 

[cdoublejj]

If you can get it cheap it's nice future proofing so. It can be used for power over Ethernet or plain old DC. I also had a free spool of coax and tossed that in the hole too. I may be be setting some gizmos to get new channels working on old TVs or co opt the garage roof antenna to the house. Do t know your setup so its just some thoughts.

 

[wyliesdiesels]

throw a direct burial Ethernet from one building to the other while your at it. no futzing with wireless repeaters and signal strength. maybe not in the same conduit though

THIS!

 

[75gmck25]

Low voltage wiring (ethernet, cable, telephone) cannot be in the same conduit as 120 or 240 volt AC electrical, but the low voltage conduit can be in the same trench.

 

[mm08822]

Low voltage wiring (ethernet, cable, telephone) cannot be in the same conduit as 120 or 240 volt AC electrical, but the low voltage conduit can be in the same trench.

Yes they can. All cables/conductors would have to have a 300v rating.

Do I recommend it? No.